Arum and his company, Top Rank Inc., sued Floyd Mayweather’s manager and his investors for $100 million in Los Angeles for allegedly breaching federal antitrust laws.

“I applaud Bob Arum and Top Rank Boxing for stepping up on behalf of fighters not only in their own stable, but all across the sport,” De La Hoya said.

“Those like Bob and myself who have spent the bulk of their lives around boxing understand that the Muhammad Ali Boxing Reform Act is a crucial piece of legislation that serves to protect boxers and enhance the sport,” he said. “Golden Boy Promotions will continue to push forward with our own lawsuit to ensure our wonderful sport continues to grow in a competitive, just manner”

De La Hoya’s Golden Boy Promotions filed a similar $300 million suit in May, alleging that Haymon and his affiliates repeatedly violated the Muhammad Ali Boxing Reform Act, which prohibits managers from also acting as promoters.

“Haymon has entered into agreements to restrain trade in a substantial portion of the market for promotion of championship-caliber boxers,” the earlier lawsuit alleges.

A representative for PBC could not immediately be reached for comment.

Haymon, who represents more than 150 fighters, has a bigger market share than any other manager and, in effect, has a monopoly on promoting TV fights, according to the complaint filed in May.

Golden Boy alleged that Haymon “conspired with Waddell & Reed Financial to violate federal and state laws aimed at protecting fighters in order to monopolize boxing.”